When Elizabeth Edwards first learned of a National Enquirer expose revealing her husband's affair, her reaction was "volcanic" and she fretted that John Edwards' infidelities would "humiliate" her and end his campaign, a campaign pollster testified today.

Veteran Democratic pollster Harrison Hickman testified on the first day of Edwards' defense and described a candidate who feared his wife's temper, particularly over his affair with his mistress Rielle Hunter.

"I don't mean to say this in a disparaging way. It was volcanic... She could get upset about things, but she was really upset about this," Hickman told the court.

Edwards lawyers claim the former senator used money received from wealthy donors to hide his affair from his wife, not to circumvent federal campaign finance laws.

"She kept saying I don't want to be humiliated. I don't want my kids to have to deal with this," Hickman remembered Elizabeth Edwards saying.

Hickman, who advised Edwards that his 2008 presidential hopes were doomed, said Edwards "did everything he could to placate Mrs. Edwards... He acquiesced to Elizabeth Edwards making decisions... She took the lead and he deferred to her."

Mrs. Edwards did not want her husband to drop out of the race for the presidency, Hickman testified, even when she got a diagnosis that her breast cancer had returned and it was terminal.

"She said she didn't want to sit home and die. She wanted her life to have a purpose... She wanted to keep it going and get him elected president," Hickman told the jury.

Elizabeth Edwards died in December 2010. She slowly learned about her husband's affair with Hunter in 2007 and became increasingly upset about each new revelation, witnesses said, once becoming so distraught she tore her blouse off on an airport tarmac and collapsed on the ground.

Edwards is charged with six counts of campaign finance violations, allegedly using nearly $1 million in donations to protect his bid for the 2008 presidential nomination and later his hopes to be named vice president or attorney general. If convicted, Edwards could be sentenced to 30 years in prison.

Also today, lawyers debated whether to allow into the record a Federal Election Commission ruling that exempted Edwards' campaign from reporting the hush money as a campaign contribution.

After reviewing the campaign's finances for four years, the FEC determined last month that money Edwards' aides collected from wealthy donors Rachel "Bunny" Mellon and Fred Baron were "not campaign contribution[s]," Lora Haggard, Edwards' 2008 chief financial officer, said today.

Much of Haggard's testimony took place while the jury was outside the courtroom as federal Judge Catherine C. Eagles determined if her testimony would be admissible.

While the FEC may have one idea about the legality of the contributions, the prosecution clearly has another.

"What the FEC ruled is not relevant," said prosecutor Jeffrey Tsai. "Whatever the FEC determined is not relevant to the criminal charges."

Edwards' defense team insists the money from Mellon and Baron was never intended as political contributions, but were personal gifts to keep his wife from finding out and to provide for his illegitimate daughter.

"They are not contributions to the campaign because they were not contributions to urge the public to vote for John Edwards," Haggard said.

Haggard said Edwards was not involved in the way records were filed with the FEC and gave no instructions to keep donations secret.

She said Edwards did "nothing" to influence the way she filed reports with the FEC.

The defense initially planned to call former FEC chairman Scott Thomas as their first witness today. Prosecutors objected to his testimony, and Eagles said she would rule on whether he would be allowed to testify.

Edwards defense hinges on how broadly the judge will interpret federal election law, even down to the word "the"